Feedback isolator



Feb. 18, 1969 .4. CAWLEY FEEDBACK ISOLATOR Filed Feb. 16, 1965 Ga n H 8 WV///////.. ,7//// Fig 2 llilllll INVENTOR. Terence J Cowley BY ATTORNEY ull'lll Fig 4 United States Patent ()flice 3,428,065 Patented Feb. 18, 1969 3,428,065 FEEDBACK ISOLATOR Terence J. Cawley, Eldred, Pa., assignor to Corning Glass Works, Corning, N.Y., a corporation of New York Filed Feb. 16, 1965, Ser. No. 433,096 US. Cl. 137-815 17 Claims Int. Cl. F15c l/14 ABSTRACT OF THE DISCLOSURE A fluid feedback isolator in a fluid passage having an emitter nozzle upstream of a constant pressure chamber and a collector downstream thereof is disclosed. The collector is disposed in a spaced, longitudinally aligned, stream intercepting relationship with said emitter, with the emitter nozzle and collector having a cross section substantially smaller than the passage within which they are located.

This invention relates to fluid operated systems and more particularly to a device for isolating or nullifying the effect of downstream disturbances or feedback in a fluid operated system, but is not limited to such applications.

For purposes of simplicity this invention will be described in connection with fiuid amplifiers. In a fluid amplifier, a fluid stream, hereinafter referred to as the power stream, issues from a nozzle or orifice constructed such that the power stream is well defined in space. A control stream is directed toward the power stream in a direction generally perpendicular thereto to provide a differential pressure or pressure gradient across the power stream. The apparatus is provided with at least two outlets or fluid recovery apertures or passages facing the power stream, which recovery apertures or passages are arranged such that when the power stream is undefiected by the control stream, all of the fluid of the power stream is directed to one of the outlet passages.

Deflection of the power stream by the control stream results in delivery of at least a portion of the power stream to the second outlet passage where some of the kinetic energy of the power stream entering the second outlet passage may be recovered, or where the fluid so directed may be delivered to a utilization device. A low energy control stream can deflect a well defined high energy power stream to the extent required to cause a substantial portion of the power stream to be delivered to the second outlet passage, while the integrity or the well defined character of the power stream is retained sufliciently a-fter interaction of the two streams so that the total energy or change in total energy delivered to the second outlet passage can be greater than the energy or change in energy required to accomplish this deflection. Therefore, since the changes in energy at the load device produced by deflection of the stream are greater than the changes in energy required to produce the deflection, the apparatus is capable of amplification and can produce a power gain. This of course is but one fluid amplifier system, and the gain achieveable with a particular system will vary and be to a degree dependent upon the spacing between the outlet passages and the nozzle from which the power stream issues.

After the power stream enters one outlet passage and the downstream flow resistance or pressure increases for any reason, such as by the functioning of the utilization device, the upstream flow decreases. In addition, any flow, for any reason, toward the power nozzle in the other outlet passage, herein called feedback, may also change the power stream flow characteristics. Clearly such flow resistance and pressure increases, or feedback, are undesirable since the power stream flow characteristics are affected by sources over which little or no control can be exercised.

It is an object of this invention to provide a means for producing a fluid amplifier power stream totally independent of any downstream flow or load changes.

Another object of this invention is to provide a means [for producing a well defined high energy fluid stream totally independent of downstream flow resistance or pressure changes, and totally independent of any feedback from any downstream source.

A further object is to obtain optimum design parameters from fluid amplifier circuitry.

Broadly, according to the instant invention a feedback isolator is provided having an emitter means for issuing a stream of fluid under pressure, a collector positioned in an intercepting relationship to said stream, and a constant pressure chamber intermediate said emitter means and said collector with said stream passing through said chamber so that its integrity is retained and a substantial portion thereof is delivered to said collector.

Additional objects, features, and advantages of the present invention will become apparent to those skilled in the art from the following detailed description and the attached drawing on which, by way of example, only the preferred embodiments of this invention are illustrated.

FIGURE 1 is a fragmentary plan view of a fluid operated device embodying the feedback isolator of this invention.

FIGURE 2 is a cross sectional elevation of the device of FIGURE 1 taken along line 2-2 thereof.

FIGURE 3 is a cross sectional elevation of the device of FIGURE 1 taken along line 33 thereof.

FIGURE 4 is a fragmentary plan view of a fluid operated device illustrating another embodiment of the feedback isolator of this invention.

FIGURE 5 is a plan view of a bistable fluid amplifier embodying the feedback isolator of this invention in two outlet apertures thereof.

The present invention may be utilized with many multistable fluid amplifiers, or other fluid operated devices wherein a high energy fluid stream passes through a passage or aperture. The stream fluid may be compressible such as air, nitrogen, or other gases, or incompressible such as water or other liquids. This invention is not limited to any particular fluid.

Referring to FIGURES l, 2, and 3, a fluid operated device 10 is illustrated comprising plates 12 and 14 and having fluid stream passages or apertures 16 and 18 formed in plate 12. Feedback isolator emitter nozzle 20 is formed terminating aperture 16. In a spaced, fluid intercepting relationship with emitter nozzle 20, and in longitudinal alignment therewith, a collector 22 is formed, which collector is connected to aperture 18. A constant pressure chamber 24, comprising channel 26 and openings 28 and 30, is formed intermediate emitter nozzle 20 and collector 22 thereby separating them. Channel 26 and openings 28 and 30 are formed in plate 12 and extend through plate 14 to the exterior of device .10. The pressure in chamber 24 is maintained constant since it is open to ambient. As is readily understood by one familiar with the art, passage 18 is a continuation of passage 16 downstream of the feedback isolator.

Plates 12 and 14 may be formed of any suitable material such as metal, glass, ceramic, plastics or the like, and are sealed or bonded together by any suitable method well known to one familiar with the art.

As a well defined high energy power stream flows through aperture 16, in the direction indicated by the arrows in FIGURE 1, it enters emitter 20. Being a well defined and high energy stream, it passes through channel 26 of chamber 24 and it is intercepted by or enters collector 22 sufficiently retaining its well defined character so that it can pass through aperture 18 and deliver sufficient energy necessary at the point of utilization, not shown. Any change of flow resistance or pressure downstream of chamber 24, such as by the functioning of a utilization device, leaks, or resulting from any cause whatever, or any low energy feedback through aperture 18, will have no affect on the quality or characteristics of the stream in aperture 16, since any such change or feedback will be dissipated in chamber 24. Suitable utilization devices are timers, digital logic circuit elements, analog circuit elements, or the like.

Referring to FIGURE 4, another embodiment of the device shown in FIGURE 1 is illustrated. Collector 32 is formed with a funnel-like section opposing emitter nozzle 20, which funnel-like section aids in maintaining a well defined power stream and also aids in dissipating any feedback.

FIGURE 5, illustrates a bistable fluid amplifier device 34, having feedback isolators of this invention formed in each of the outlet apertures thereof. Such a device may also be formed of two plates such as that described in connection with the devices of FIGURES l-3, however, for the purposes of clarity the upper plate 36 is shown as being transparent. A suitably regulated fluid stream supplied by a compressor, pump, or like source, not shown, enters aperture 38. The fluid stream passes through nozzle 40 and emerges therefrom as a well defined high energy power stream. A pair of outlet passages 42 and 44 are formed at the outlet of nozzle 40.

The outer walls of the inverted V formed by outlet passages 42 and 44, that is the left wall of passages 42 and the right wall of passage 44, are set back from nozzle 40 so that, in accordance with Bernoullis Theorem, the high energy power stream issuing from nozzle 40 can create a region of low pressure adjacent either of these walls causing the stream to lock-on to such wall. Such a condition is maintained as long as fluid is supplied to aperture 38 and nothing disturbs the power stream.

Two control signal input apertures 46 and 48 are provided for control purposes. If the power stream is lockedon the left wall of passage 42 and a pressure is applied to aperture 46, a control stream will issue from control nozzle 50 causing it to impinge on the power stream, displacing the power stream and causing it to lock-on to the right wall of passage 44. The opposite is also true. When the power stream is locked-n to the right wall of passage 44, and a pressure is applied to aperture 48, a control stream will issue from control nozzle 52 displacing the power stream again, causing it to lock-on to the left wall of passage 42.

A common constant pressure chamber 54 is formed across and intermediate the ends of both outlet passages 42 and 44. Chamber 54 comprises channels 56 and 58, and openings 60, 62, and 64. As the high energy power stream flows through passage 42, it passes through emitter nozzle 66, channel 56 and enters collector 68, from which it flows through passage 70, which passage 70 is obviously that portion of outlet passage 42 that is downstream of collector 68, to a point of utilization. When the high energy power stream flows through passage 44, it passes through emitter nozzle 72, channel 58, and enters collector 74, from which it flows through passage 76, which passage 76 is obviously that portion of outlet passage 44 that is downstream of collector 74, again to a point of utilization. Any downstream increase in flow resistance or pressure, or any feedback through either aperture 70 or 76, regardless through which one the power stream happens to be flowing, will be dissipated by chamber 54 and no affect from such disturbances will be communicated to the power stream upstream of chamber 54.

A typical example of a feedback isolator embodied within a fluid amplifier such as that illustrated in FIG- URE is as follows. The emitter nozzle and collector have a width of 0.030 inch and a height the same as the power stream nozzle of 0.040 inch. The constant pressure chamber has a width, that is the spacing between the emitter nozzle and collector, of 0.020 inch and a length of 0.090 inch. The chamber openings are 0.080 inch in diameter. A power stream having a pressure of 2 p.s.i. upstream of a feedback isolator having the above dimensions has been found to emerge from the isolator having a pressure of approximately 1.9 p.s.i.

With the width of the power stream nozzle being W, it has been found that the preferred emitter nozzle and collector widths are from approximately W to approximately lOW while maintaining the same height. Further, it has been found that the preferred width of the constant pressure chamber is at least 2W. Neither the length of the chamber channel nor the size of the chamber openings are critical.

One familiar with the art will readily understand that the final design parameters of any specific feedback isolator will at least in part depend on the fluid density, temperature, and pressure, as well as the characteristics required of the power stream at the point of utilization. It must be noted that for proper operation, the width of the constant pressure chamber channel must :be of such size that the well defined high energy stream can pass through it, while downstream disturbances, or changes are dissipated by it.

Although the present invention has been described with respect to specific details of certain embodiments thereof, it is not intended that such details be limitations upon the scope of the invention except insofar as set forth in the following claims.

I claim:

1. In a fluidic system a feedback isolator comprising means for issuing a stream of fluid under pressure,

a collector for receiving said stream having a cross section of substantially the same size as that of said means positioned in a stream intercepting relationship with said means, and an elongated chamber intermediate said means and said collector opened to ambient atmosphere along its length including that portion which separates said collector from said means, said stream being passable through said chamber.

2. The feedback isolator of claim 1 wherein said fluid is a gas.

3. The feedback isolator of claim 1 wherein said fluid is a liquid.

4. A feedback isolator for a fluidic system comprising means for issuing a well defined high energy fluid stream disposed within a fluid passage,

a collector for receiving said stream disposed within said passage in a spaced, stream intercepting relationship and in longitudinal alignment with said means, said means and said collector having a cross section substantially smaller than that of said passage, and

an elongated chamber intermediate said means and said collector opened to ambient atmosphere along its length including that portion which separates said collector from said means, said stream being passable through said chamber.

5. Adevice comprising a fluid amplifier of the type having interconnected fluid passages whereby a well defined high energy fluid stream may flow from an inlet nozzle to any one of a plurality of outlet passages,

nozzle means substantially smaller in width than said outlet passages for channeling said well defined high energy fluid stream through such outlet passages disposed intermediate the ends of at least one of said plurality of outlet passages,

a collector in a spaced, longitudinally aligned, stream intercepting relationship with each of said means, for receiving said stream, said collector having a cross section substantially smaller than that of said passages, and

an elongated chamber intermediate said means and said collector opened to ambient atmosphere along its length including that portion which separates said 14. A device comprising a fluid amplifier of the type having interconnected fluid passages whereby a well defined high energy fluid stream may flow from an inlet nozzle having a width W to any one of a plurality of outlet passages,

collector from said means, said stream being pas- 5 an emitter nozzle having a width ranging from apsable through said chamber. proximately W to approximately 10W disposed in- 6. The device of claim 5 wherein said fluid is a gas. termediate the ends of at least one of said plurality 7. The device of claim 5 wherein said fluid is a liquid. of outlet passages, 8. A feedback isolator for a fluidic system comprising 10 a collector for receiving said stream having a width an emitter nozzle for issuing a well defined high enranging from approximately W to approximately ergy stream disposed within a fluid passage, 10W disposed in a spaced, longitudinally aligned, a collector disposed within said passage in a spaced, stream intercepting relationship with said emitter longitudinally aligned, stream intercepting relationnozzle, and ship with said nozzle for receiving said stream, said an elongated chamber intermediate said emitter nozzle collector having a funnel like portion facing said and said collector opened to ambient atmosphere nozzle, said nozzle and said collector having a cross along its length including that portion which sepsection substantially smaller than that of said pasarates said collector from said emitter nozzle, said sage, and stream being passable through said chamber. an elongated chamber intermediate said emitter nozzle 15. The device of claim 14 wherein the width of said and said collector opened to ambient atmosphere along its length including that portion which separates said collector from said emitter nozzle, said stream being passable through said chamber.

chamber at said portion which separates said collector from said emitter nozzle is at least 2W.

16. A feedback isolator for a fluidic system comprising means for issuing a well defined high energy fluid 9. A fluid operated system comprising stream disposed within a fluid passage,

a fluid amplifier of the type having interconnected fluid a collector within said passage for receiving said stream passages whereby a well defined, high energy fluid having a cross section of substantially the same size stream may flow from an inlet nozzle to at least as that of said means, said collector being disposed one of a plurality of outlet passages, in a spaced, stream intercepting relationship and in an emitter nozzle disposed intermediate the ends of longitudinal alignment with said means, said means at least one of said plurality of outlet passages, and said collector having a cross section substantially a collector in a spaced, longitudinally aligned, stream smaller than that of said passage, and

intercepting relationship with each of said emitter an elongated chamber intermediate said means and nozzles for receiving said stream, said nozzle and said collector opened to ambient atmosphere along said collector having a cross section substantially 30 its length including that portion which separates said smaller than that of said passages, an elongated chamber intermediate said emitter nozzle and said collector opened to ambient atmosphere collector from said means, said stream being passable through said chamber. 17. The feedback isolator of claim 16 wherein the width of said chamber at said portion which separates said collector from said means is up to about the width of said collector and said means.

along its length including that portion which separates said collector from said emitter nozzle, said 4 stream being passable through said chamber, and

utilization means arranged to thereafter receive the stream fluid, said stream upstream from said chamber being insensitive to changes in stream conditions downstream from said chamber.

References Cited UNITED STATES PATENTS 10. The system of claim 9 wherein each said collector 236113-172 3 gl has a funnel-like portion facing each said emitter nozzle. 3 33 5 4 at a 7 8 11. The system of dam 9 whereln said fluid 1s a gas. 3:336:931 8/1967 FOX et a1. 137815 12. The system of claim 9 wherein said fluid is a liquid.

13. The system of claim 9 wherein said collector has a cross section of substantially the same size as that of said emitter nozzle.

SAMUEL SCOTT, Primary Examiner. 

